Tumor M2-PK

Tumor M2-PK is a synonym for the dimeric form of the pyruvate kinase isoenzyme type M2 (PKM2), a key enzyme within tumor metabolism. Tumor M2-PK can be elevated in many tumor types, rather than being an organ-specific tumor marker such as PSA. Increased stool (fecal) levels are being investigated as a method of screening for colorectal tumors, and EDTA plasma levels are undergoing testing for possible application in the follow-up of various cancers.

Sandwich ELISA’s based on two monoclonal antibodies which specifically recognize Tumor M2-PK (the dimeric form of M2-PK) are available for the quantification of Tumor M2-PK in stool and EDTA-plasma samples respectively. As a biomarker, the amount of Tumor M2-PK in stool and EDTA-plasma reflects the specific metabolic status of the tumors.

Early detection of colorectal tumors and polyps

M2-PK, as measured in feces, is a potential tumor marker for colorectal cancer. When measured in feces with a cutoff value of 4 U/ml, its sensitivity has been estimated to be 85% (with a 95% confidence interval of 65 to 96%) for colon cancer and 56% (confidence interval 41–74%) for rectal cancer. Its specificity is 95%.